Isn't it the same game as Ground Zeroes? They were just "announced" as two different games but it's supposed to be the same now.

"The Phantom Pain was originally announced as two games, one titled Ground Zeroes and one titled The Phantom Pain. Kojima Productions and Konami did not confirm their involvement on The Phantom Pain and instead announced The Phantom Pain under the fake pseudonym of Moby Dick Studio. The two games were thought to be separate until, after fan suspicion, they were revealed to be the same in early 2013."

The really painful introduction is MGS2, as it features more Raiden and Snake (we're assuming this is the first FMA you play with no prior knowledge of the characters.)

He's referring to the fact he played the 3DS version of MGS3.

You're both wrong (yes the 3DS is version is terrible). Snake Eater (just like Guns of the Patriots) is quite possibly the worst installment to start off with.

There's a reason Metal Gear Solid 1 has the number one in it. Starting Snake Eater and venturing forward would confuse even Ghandi. It's a prequel with character development that foreshadows its sequels. One thing you would know nothing of.